> > Use FS_SAFE for "fuse" fs type, but not for "fuseblk".> > > > FUSE was designed from the beginning to be safe for unprivileged> > users. This has also been verified in practice over many years.> > How does FUSE do this?> > There are obvious cases like crafting a filesystem which has setuid executables> or world-writeable device nodes or whatever. I'm sure there are lots of other> cases.> > Where is FUSE's implementation of all this protection described?

Most of it is in Documentation/filesystems/fuse.txt, some of it iscode comments.